Todd R. Younkin

Learn More
Compact, low capacitance optical modulators are vital for efficient, high-speed chip to chip optical interconnects. Electro-optic (EO) polymer cladding micro-ring resonator modulators have been fabricated and their performance is characterized. Optical modulators with ring diameters smaller than 50 microm have been demonstrated in a silicon nitride based(More)
Three strategies for approaching the design and synthesis of non-chemically amplified resists (non-CARs) are presented. These are linear polycarbonates, star polyester-blk-poly(methyl methacrylate) and comb polymers with polysulfone backbones. The linear polycarbonates were designed to cleave when irradiated with 92 eV photons and high Tg alicyclic groups(More)
A series of high-performance polycarbonates have been prepared with glass-transition temperatures and decomposition temperatures that are tunable by varying the repeat-unit chemical structure. Patterning of the polymers with extreme UV lithography has been achieved by taking advantage of direct photoinduced chain scission of the polymer chains, which(More)
Probing chemical reaction kinetics in the near-solid state (small molecules and polymers) is extremely challenging because of the restricted mobility of reactant species, the absence of suitable analytical probes, and most critically the limited temperature stability of the materials. By limiting temperature exposure to extremely short time frames(More)
Neutral Ni(II) salicylaldimine catalysts (pendant ligand NCMe or PPh3) were used to copolymerize ethylene with monomers containing esters, alcohols, anhydrides, and amides and yielded linear functionalized polyethylene in a single step. -Olefins and polycyclic olefin comonomers carrying functionality were directly incorporated into the polyethylene backbone(More)
Five new compounds were synthesized for use as acid amplifiers in EUV (13.5 nm) photoresists. Four compounds act as acid amplifiers and decompose by autocatalytic kinetics to generate fluorinated sulfonic acids, essential for the simultaneous improvement of resolution, sensitivity, and line edge roughness (LER) in EUV photoresists. The decomposition rates(More)
Based on reflective optics at 13.5 nm, extreme-UV lithography is the ultimate top-down technique to define structures below 22 nm but faces several challenges arising from the discrete nature of light and matter. Owing to the short wavelength, mask surface roughness plays a fundamental role in the increase of speckle pattern contrast, compromising the(More)
Here we present the relative sensitivity of EUV resists to out of band radiation (OOB), specifically wavelengths in the range 157 400 nm. EUV light sources have specifications limiting the allowed energy output in that spectral range yet there is little data supporting the specified values. Filters might be required to meet the spectral purity(More)
The diagnostic residual gas analyzer (DRGA) system to be used during ITER tokamak operation is being designed at Oak Ridge National Laboratory to measure fuel ratios (deuterium and tritium), fusion ash (helium), and impurities in the plasma. The eventual purpose of this instrument is for machine protection, basic control, and physics on ITER. Prototyping is(More)